Django loop – remove last comma - django

I have the following loop set up, but need to remove the comma on the last item (it's to replicate a JSON array for cycle2)
{% for product_in_series in series.get_products %}{%spaceless%}
{% with product_in_series.product as product %}
{%if not forloop.first%}
"<img src='{% version product.get_overview 'page_image' %}'>",
{%endif%}
{% endwith %}
{%endspaceless%}{% endfor %}
Cheers,
R

What about this?
{% for product_in_series in series.get_products %}{%spaceless%}
{% with product_in_series.product as product %}
{%if not forloop.first%}
"<img src='{% version product.get_overview 'page_image' %}'>"
{%if not forloop.last%},{%endif%}
{%endif%}
{% endwith %}
{%endspaceless%}{% endfor %}

{{ forloop.last|yesno:",,"|safe }}
, - is a comma

None of the above works for me.
The correct syntax, as in Django 3.0, is as such
{% with querythisandthat as A %}
{% for u in A %} {{ u.interesting_stuff }}
{% if u == A.last %} . {% else %} ; {% endif %}
{% endfor %}
{% endwith %}
The reason is that A.last is not True/False, but it is the last element of the queryset
https://docs.djangoproject.com/en/3.0/ref/models/querysets/#django.db.models.query.QuerySet.first

Related

Flaks / Jinja nested if statement

I am stuck on a nested if statement, thinking I am approaching it wrong. I have a list of about 100 products that I am rendering on my page. I want to have a nested 'if' statement. Users will have a toolkit, and if the product is in their toolkit, i want to render "Already Uses", else "Add to toolkit?"
{% for product in products|sort(attribute="name") %}
{{ product.name }}
{% for products in toolkit %}
{% if product.name in toolkit %}
<p>Already Uses<p>
{% else %}
<p>Add to toolkit?<p>
{% endif %}
{% endfor %}
more details on: jinja2 check if value exists in list of dictionaries
You are spot on and on the right path. It would help to provide the structure (as an example) of the product object ...
{% for product in products|sort(attribute="name") %}
{{ product.name }}
{% if product.name in toolkit %}
<p>Already Uses<p>
{% else %}
<p>Add to toolkit?<p>
{% endif %}
{% endfor %}
If toolkit is a nested map map:
{% if product.name in toolkit|map(attribute="<whatever has the value equal with product.name>") %}
<p>Already Uses<p>
{% else %}
<p>Add to toolkit?<p>
{% endif %}

How to display text if the field is empty?

How to display a text if the field is empty ?
I tried the following code but it does not work :
{% if content.field_description is not empty %}
{{ content.field_description }}
{% else %}
test
{% endif %}
If you have Twig Tweak installed, you can do the following:
{% if content['field_description'] | field_value != '' %}
{{ content['field_description'].value | striptags }}
{% else %}
<p class="des-empty">test</p>
{% endif %}
When field is empty it is not coming with content variable
so you can simply check by isset
{% if content.field_description %}
{{ content.field_description }}
{% else %}
<p class="des-empty">test</p>
{% endif %}
The below worked for me:
{% if content['field_description'] IS NOT EMPTY %}
{{ content['field_description'].value | striptags }}
{% else %}
<p class="des-empty">test</p>
{% endif %}
Please note that it may vary based on the content type and fields you are dealing with.

how to do assignments for variable in django template tag

I want to do assignment in Django template tag for this code:
{% for ins in ob %}
{% if ins.heur = 'here' %}
a==1
some stuff ..
{% endif %}
{% endfor %}
{% if a!=1 %}
stuff
{% endif %}
You can use the {% with %} template tag.
Example:
{% with a=1 %}
{{ a }}
{% endwith %}

Django template: check for empty query set

Is there a way to check for an empty query set in the Django template? In the example below, I only want the NOTES header to be displayed if there are notes.
If I put an {% empty %} inside the "for" then it does display whatever is inside the empty tag, so it knows it's empty.
I'm hoping for something that does not involve running the query twice.
{% if notes - want something here that works %}
NOTES:
{% for note in notes %}
{{note.text}}
{% endfor %}
{% endif %}
Clarification: the above example "if notes" does not work - it still displays the header even with an empty query set.
Here's a simplified version of the view
sql = "select * from app_notes, app_trips where"
notes = trip_notes.objects.raw(sql,(user_id,))
return render_to_response(template, {"notes":notes},context_instance=RequestContext(request))
Edit: the view select selects from multiple tables.
Have a look at the {% empty %} tag.
Example from the documentation
<ul>
{% for athlete in athlete_list %}
<li>{{ athlete.name }}</li>
{% empty %}
<li>Sorry, no athletes in this list.</li>
{% endfor %}
</ul>
Link: https://docs.djangoproject.com/en/1.8/ref/templates/builtins/#for-empty
If you are interested in a table, or some kind of heading if there are results, add the forloop.first:
{% for athlete in athlete_list %}
{% if forloop.first %}
Athlete Name:
{% endif %}
{{ athlete.name }}
{% empty %}
Sorry, no athletes in this list.
{% endfor %}
Try {% if notes.all %}. It works for me.
In your view check whether notes is empty or not. If it is then you pass None instead:
{"notes": None}
In your template you use {% if notes %} as normal.
It's unfortunate that you're stuck using a raw query set - they're missing a lot of useful behavior.
You could convert the raw query set into a list in the view:
notes_as_list = list(notes)
return render_to_response(template, {"notes":notes_as_list},context_instance=RequestContext(request))
Then check it as a boolean in the template:
{% if notes %}
Header
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
You could also make it happen without conversions using forloop.first:
{% for note in notes %}
{% if forloop.first %}
Header
{% endif %}
{{ note.text }}
{% endfor %}
What about:
{% if notes != None %}
{% if notes %}
NOTES:
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
{% else %}
NO NOTES AT ALL
{% endif %}
Your original solution
{% if notes %}
Header
{% for note in notes %}
{{ note.text }}
{% endfor %}
{% endif %}
Works now with Django 1.7 and thanks to QuerySet caching, it does not cost and extra query.
Often the right way to do this is to use the {% with ... %} tag. This caches the query so it runs only once and also gives you more flexibility with your markup than using {% empty %}.
{% with notes as my_notes %}
{% if my_notes %}
<ul>
{% for note in my_notes %}
<li>{{ note }}</li>
{% endfor %}
</ul>
{% else %}
<p>Sorry, no notes available</p>
{% endif %}
{% endwith %}
With this particular example I'm not sure how useful it is but if you're querying Many-to-Many field, for instance, it's likely what you want to do.
Use {% empty %} in django templates
{% if list_data %}
{% for data in list_data %}
{{ data.field_1 }}
{% endfor %}
{% else %}
<p>No data found!</p>
{% endif %}
We can write above code with {% empty %}.
{% for data in list_data %}
{{ data.field_1 }}
{% empty %}
<p>No data found!</p>
{% endfor %}

How do I check for last loop iteration in Django template?

I have a basic question, in the Django template language how can you tell if you are at the last loop iteration in a for loop?
You would use forloop.last. For example:
<ul>
{% for item in menu_items %}
<li{% if forloop.last %} class='last'{% endif %}>{{ item }}</li>
{% endfor %}
</ul>
{{ forloop.last }}
You can basically use this logic in a for loop:
{% if forloop.last %}
# Do something here
{% endif %}
For example, if you need to put a comma after each item except for the last one, you can use this snippet:
{% for item in item_list %}
{% if forloop.last %}
{{ item }}
{% else %}
{{ item }},
{% endif %}
{% endfor %}
which will become for a list with three items:
first_item, second_item, third_item